At this moment when the increasing dementia old people become a social issue, it may well be important to approach in a variety of ways to its socio-environmental treatment or the nusing intevention in its secondary mental disorder. With such a basic conception in mind, this study was aiimed atdetermining the effects of the musical thereby, suggesting the methods of nursing intervention to helpthem live a quality life. To this end, the test groupwas checked once before the therapy, and four times thereafter(first, second, third and fourth week). In short, this this study was designed as pre- and post-test for a single test group. The test group consisting of 20 dementia old people were sampled from those who had visited an old people's welfare center in Seoul to be treated for their dementia symptom from July 30 to Auguest 27. 1998. For this survey, the researcher developed a scale based on "the Behavioral and Emotional Scale invented by Wyatt & Kupfer(1968) after having consulted the experts and proven its validity. this tool consisted of 59 items. The tool or tape of the musical therapy was edited by selecting old people 's favoite songs (changes, folk songs and children's songs). The test group was subject to 3 rounds of the musical therapy a day for a month. It would take half an hour to complete one round of the therapy which consisted of music listening, rhythmic instrument playing and following up singing. The therapy was performed at the lounge of the center to which the sample people could get access conveniently. A nurse was asked to observe sample people's demaentia behaviors or emotion and thereupon, evaluated hem accorrding to the checklist scale. The collected data were processed using the SPSS program for absolute values, percentiales, mean, SDand Paired T Test, While such values as item-wise decrease ratio of dependent variables, decrease ratio by specific item and changes after the therapy were examined by means of percentiles. The item of scale and its reliability were analyzed with Cronbach alpha, which was found to be .8923. The results of this study can be summarized as follows; 1. As a result of analyzing dementia old people's behaviors nd emotin before and after the therapy (once and four times, resspectively), it was found that the disoder of perception functions was most outstanding. 2. After the therapy, the decrease was most apparent in "depression mood" out of the dementia behaviors and emotion. 3. After the therapy, the decrease was most outstanding in such specific items as "depression" and "overaction". 4. As a consequence of analyzing the changes caused by the therapy, it was disclosed that sample people's overallbehaviors and emotions had been decreased, which suggests that the musical therapy may be an kjeffective nursing intervention for the treatment of dementia. 5. Hypothesis Ⅰ: The hypothesis I that "dementia behaviors and emotion would be less after the musical treatment than before it" was supported. 6. Hypothesis Ⅱ. : The hypothesis Ⅱ that "the musical therapy would be more effective on light dementia than heavy one" was also supported. As discussed above, it has been proved through this study that the musical therapy consisting of such traditional songs favored by old people as changes, folk songs, old popular songs and children's songs has an effect on the treatment of dementia may be better treatted by the therapy than the heavy symptoms. Furthermore, it is deemed desirable to apply the musical therapy on a continual basis for 3~4 weeks or longer rather than stop it in 1~2 weeks. After all, it may well be concluded that the musidal therapy is an effective nursing intevention to provide the dementia old people with a quality service and thereby, reduce the problematic behaviors and therebyreduce the problematic behaviors and emotion. Lastly, it is hoped that thiss study would be followed up by another similar studies, if we want to develop a longer-term and systematic musical therapy befitting our sentiment and thereby, contribute to the development of an independent nusing area under the circumstance of poor dementia treatments.